Helper class for creating and parsing JSON data.
The [JSON] enables all data types to be converted to and from a JSON string. This useful for serializing data to save to a file or send over the network.
[method stringify] is used to convert any data type into a JSON string.
[method parse] is used to convert any existing JSON data into a [Variant] that can be used within Godot. If successfully parsed, use [member data] to retrieve the [Variant], and use [code]typeof[/code] to check if the Variant's type is what you expect. JSON Objects are converted into a [Dictionary], but JSON data can be used to store [Array]s, numbers, [String]s and even just a boolean.
[b]Example[/b]
[codeblock]
var data_to_send = ["a", "b", "c"]
var json_string = JSON.stringify(data_to_send)
# Save data
# ...
# Retrieve data
var error = json.parse(json_string)
if error == OK:
var data_received = json.data
if typeof(data_received) == TYPE_ARRAY:
print(data_received) # Prints array
else:
print("Unexpected data")
else:
print("JSON Parse Error: ", json.get_error_message(), " in ", json_string, " at line ", json.get_error_line())
[/codeblock]
Alternatively, you can parse string using the static [method parse_string] method, but it doesn't allow to handle errors.
[codeblock]
var data = JSON.parse_string(json_string) # Returns null if parsing failed.
[/codeblock]
[b]Note:[/b] Both parse methods do not fully comply with the JSON specification:
- Trailing commas in arrays or objects are ignored, instead of causing a parser error.
- New line and tab characters are accepted in string literals, and are treated like their corresponding escape sequences [code]\n[/code] and [code]\t[/code].
- Numbers are parsed using [method String.to_float] which is generally more lax than the JSON specification.
- Certain errors, such as invalid Unicode sequences, do not cause a parser error. Instead, the string is cleansed and an error is logged to the console.
Returns [code]0[/code] if the last call to [method parse] was successful, or the line number where the parse failed.
Returns an empty string if the last call to [method parse] was successful, or the error message if it failed.
Attempts to parse the [param json_string] provided.
Returns an [enum Error]. If the parse was successful, it returns [constant OK] and the result can be retrieved using [member data]. If unsuccessful, use [method get_error_line] and [method get_error_message] for identifying the source of the failure.
Non-static variant of [method parse_string], if you want custom error handling.
Attempts to parse the [param json_string] provided and returns the parsed data. Returns [code]null[/code] if parse failed.
Converts a [Variant] var to JSON text and returns the result. Useful for serializing data to store or send over the network.
[b]Note:[/b] The JSON specification does not define integer or float types, but only a [i]number[/i] type. Therefore, converting a Variant to JSON text will convert all numerical values to [float] types.
[b]Note:[/b] If [param full_precision] is [code]true[/code], when stringifying floats, the unreliable digits are stringified in addition to the reliable digits to guarantee exact decoding.
The [param indent] parameter controls if and how something is indented, the string used for this parameter will be used where there should be an indent in the output, even spaces like [code]" "[/code] will work. [code]\t[/code] and [code]\n[/code] can also be used for a tab indent, or to make a newline for each indent respectively.
[b]Example output:[/b]
[codeblock]
## JSON.stringify(my_dictionary)
{"name":"my_dictionary","version":"1.0.0","entities":[{"name":"entity_0","value":"value_0"},{"name":"entity_1","value":"value_1"}]}
## JSON.stringify(my_dictionary, "\t")
{
"name": "my_dictionary",
"version": "1.0.0",
"entities": [
{
"name": "entity_0",
"value": "value_0"
},
{
"name": "entity_1",
"value": "value_1"
}
]
}
## JSON.stringify(my_dictionary, "...")
{
..."name": "my_dictionary",
..."version": "1.0.0",
..."entities": [
......{
........."name": "entity_0",
........."value": "value_0"
......},
......{
........."name": "entity_1",
........."value": "value_1"
......}
...]
}
[/codeblock]
Contains the parsed JSON data in [Variant] form.